1. The Field of the Invention
This invention relates to apparatus and methods for electrolyzing fluids and more particularly relates to apparatus and methods for electrolyzing saline solutions for use as antimicrobial agents.
2. The Prior Art
It has long been known that the electrolysis of fluids can result in useful products. In particular, the electrolysis of saline solution results in the production of chlorine and ozone. It is known that the products resulting from the electrolysis of saline solutions are useful as in vitro microbicides for hard surfaces. Thus, various apparatus and methods have been proposed for electrolyzing saline solution, however, all of the previously available schemes present one or more drawbacks. For example, while the electrolyzed saline solution is useful in some cases as an in vitro microbicide, past uses have posed problems and may not destroy harmful pathogens. Moreover, the drawbacks of previously proposed schemes for electrolyzed saline solution are particularly disadvantageous when the electrolyzed saline solutions are to be used for in vivo administration.
For example, U.S. Pat. Nos. 4,236,992, 4,238,323, and 4,316,787 all to Themy disclose an electrode, method and apparatus for electrolyzing dilute saline solutions to produce effective amounts of disinfecting agents such as chlorine, ozone and hydroxide ions. Significantly, the devices disclosed in Themy all are inefficient, produce unpredictable results, and potentially introduce undesirable and toxic substances into the electrolyzed solution. The unpredictable results obtained using the devices disclosed in Themy makes the resulting product unsuitable for use as an antimicrobial agent. Moreover, the introduction of undesirable and toxic substances into the electrolyzed solution is of critical concern when the solution is to be administered in vivo to a patient.
Another apparatus for producing electrolyzed saline solutions has been available under the trade name Ster-O-Lizer. Laboratory reports and other data available from testing of electrolyzed saline solutions from various Ster-O-Lizer models have shown that it is effective in keeping water free of pathogenic organisms. Tests conducted in vitro further show that certain microorganisms, inclusive of Pseudomonas aeruqinosa, Escherichia coli, Staphylococcus aureus, Candida albicans, and Salmonella typhi, are non-infectious after exposure to electrolyzed saline solutions. Nevertheless, devices such as those available under the trade name Ster-O-Lizer do not address the particular problems which are posed when medical or dental equipment is to be sterilized. Such devices also do not address the critical concerns which arise when the resulting solution is to be administered in vivo to a patient.
For many years, ozone (O.sub.3) has been used for the treatment of viral infections. Chlorine, in the form of chlorinated lime, was used successfully as early as 1846 to prevent and fight puerperal fever. By 1911, the United States purified as much as 800,000,000 gallons of water through the chlorination process. Wide use of chlorine as a 0.05% sodium hypochlorite solution (Dakins Solution) for treatment of open and infected wounds began in 1915. Dakins Solution was a standard product up to 1963 which was listed in the British Pharmacopeia.
As reported by Wilk et al., International Congress on Technology and Technology Exchange, First Euro-American symposium, Paris, France (1992) and Science, Total Environment, 63:191-197 (1987), certain combinations of ozone and chlorine have significantly greater activity than either used separately against a variety of bacteria including Staphylococcus aureus and Pseudomonas aeruginosa. Candida albicans was also reported to be effectively killed by a combination of ozone and chlorine.
In view of the many uses of chlorine and ozone, numerous apparatus and methods have been proposed for generating chlorine and ozone. Significantly, the previously available apparatus and methods have not been well-suited to producing electrolyzed saline containing correct amounts of ozone and chlorine for in vitro destruction of microbes on health care equipment or in vivo treatment of physiological fluids for the destruction of microbes in warm blooded animals, including humans. It has recently been discovered that there are situations where physiological fluids can be beneficially treated using electrolyzed saline solutions. The treatment of physiological fluids such as whole blood, plasma or cell isolates by electrolyzed saline solution, said treatment rendering these fluids benign from infectious organisms without destroying the therapeutic characteristics of such fluids, is now possible. Disadvantageously, the available apparatus and methods for generating chlorine and ozone are not well-suited for either in vitro destruction of microorganisms or for either in vitro or in vivo treatment of physiological fluids such as whole blood, plasma, or cell isolates.
Methods for treatment of physiological fluids using electrolyzed solutions are set forth in U.S. Pat. No. 5,334,383 and U.S. patent application Ser. No. 08/275,904 filed Jul. 15, 1994, both of which are now incorporated herein by reference in their entireties. In these documents, an electrolyzed saline solution, properly made and administered in vivo, is effective in the treatment of various infections brought on by invading antigens and particularly viral infections. Thus, it would be a great advance in the art to provide an apparatus and method for electrolyzing saline solution for administration in vivo.
There is also great concern in the health care profession with the transfer of infectious organisms from one patient to another. In many cases, the concern over cross contamination between patients has lead to the development and use of health care equipment which, rather than being sterilized and reused, is disposed of after a single use eliminating any possibility of cross contamination of infectious organisms between patients due to reuse of that equipment. In many instances of health care equipment, it is impossible or impractical to dispose of all components after contact with a single patient. While a properly maintained and operated autoclave will kill all pathogens, many items of health care equipment are damaged or destroyed by the high temperatures used in an autoclave. Thus, it would also be an advance in the art to provide a system and method for disinfecting and/or sterilizing health care equipment to prevent the transfer of harmful pathogens from one patient to another patient.